Joining things up into a coherent whole is never easy but it is a mark of competence. First of all, you need to have a clear focus of what the endgame is and then you need to understand what needs to be done to get there. The rest is about implementation.

New reports last week noted Hong Kong's very poor roadside air quality. Despite a decade of effort, conditions remain a daily threat to the public health of this city's people. Government spin focuses on 'achievements' - that there have been some reductions in pollutant levels, based on levels of a certain year in the past. In reality, absolute levels remain very high and, when compared with the World Health Organisation's recommended air quality standards, Hong Kong's street-level air quality is positively dangerous.

Instead of recounting how well officials rearranged the deck chairs on the Titanic, the government may want to ask itself how it could have averted the roadside air crisis over the past decade. There is no point repeating what it has done - we know officials switched taxis and most minibuses from diesel to LPG, and ultra-low-sulphur diesel has been made available, for example - but the measures have not been enough. So, with the benefit of hindsight, we should ask: if our officials had to do it all over again, what other steps would they have taken?

The answer is that they should have taken numerous, related steps that affect roadside air quality. If the government wants to have any chance of cleaning up our roadside air, it needs to not only focus on what comes out of exhausts but also to change direction. Measures include taking the oldest, most-polluting trucks off the road, and converting buses running along urban routes to run on natural gas.

A more challenging solution is to reduce vehicles on our roads altogether. This means investing in railways, which is finally happening now but, until relatively recently, the emphasis had been on building roads. It also requires officials to co-ordinate road and rail interchanges so people opt to take the train into denser urban areas, and fewer empty buses. That kind of co-ordination requires a clear focus on the public health endgame.

That hasn't happened, because officials were focused elsewhere. Their priority was roads. Even though some corner of the bureaucracy knew that Hong Kong must follow a rail-led public transport policy - which had been articulated - it was not followed in practice because some other parts of the administration built roads and were sympathetic to providing cheap road transport. The government could just as well have provided cheaper rail transport by subsidising rail construction to keep fares down, which it seems to be finally doing.

The city's topography poses another challenge. Urban areas are dominated by tall buildings and narrow streets with heavy traffic. Emissions from vehicles gets trapped in 'street canyons' that become extremely polluted and endanger public health. The solution for cleaning the city air should have involved a change in urban planning, in which vehicles were removed from the picture through massive pedestrian schemes. Again, officials have been too timid. There have only been small-scale schemes here and there. Instead, officials have allowed the 'walled-buildings' phenomenon to spread across the city. In addition to street canyons, we now have massive buildings blocking air circulation in many places.

The failure in all these policy areas to fight roadside pollution is the reason for this crisis. Our officials continue to avoid admitting publicly that our roadside air quality is extremely poor. If they did, pressure would mount on them to take action. But they cannot connect all the dots for what needs to be done because there is no policy focus or priority for improving air quality for the sake of people's health.

Things won't get better until officials adopt a new outlook. When will our political leaders take the lead and speak out, for the sake of our health?